/**
 * 
 */
package org.mspring.platform.support.feed.atom;

import java.util.ArrayList;
import java.util.Date;
import java.util.List;
import java.util.TimeZone;

import org.apache.commons.lang3.time.DateFormatUtils;

/**
 * @author Gao Youbo
 * @since May 12, 2012
 */
public final class Feed {
    /**
     * Id.
     */
    private String id;
    /**
     * Title.
     */
    private String title;
    /**
     * Subtitle.
     */
    private String subtitle;
    /**
     * Update date.
     */
    private Date updated;
    /**
     * Author.
     */
    private String author;
    /**
     * Link.
     */
    private String link;
    /**
     * Entries.
     */
    private List<Entry> entries = new ArrayList<Entry>();
    /**
     * Link variable.
     */
    private static final String LINK_VARIABLE = "${link}";
    /**
     * Time zone id.
     */
    public static final String TIME_ZONE_ID = "Asia/Shanghai";
    /**
     * Start document.
     */
    private static final String START_DOCUMENT = "<?xml version=\"1.0\"?>";
    /**
     * Start feed element.
     */
    private static final String START_FEED_ELEMENT = "<feed xmlns=\"http://www.w3.org/2005/Atom\">";
    /**
     * End feed element.
     */
    private static final String END_FEED_ELEMENT = "</feed>";
    /**
     * Start id element.
     */
    private static final String START_ID_ELEMENT = "<id>";
    /**
     * End if element.
     */
    private static final String END_ID_ELEMENT = "</id>";
    /**
     * Start title element.
     */
    private static final String START_TITLE_ELEMENT = "<title type=\"text\">";
    /**
     * End title element.
     */
    private static final String END_TITLE_ELEMENT = "</title>";
    /**
     * Start subtitle element.
     */
    private static final String START_SUBTITLE_ELEMENT = "<subtitle type=\"text\"> ";
    /**
     * End subtitle element.
     */
    private static final String END_SUBTITLE_ELEMENT = "</subtitle>";
    /**
     * Start updated element.
     */
    private static final String START_UPDATED_ELEMENT = "<updated>";
    /**
     * End updated element.
     */
    private static final String END_UPDATED_ELEMENT = "</updated>";
    /**
     * Start author element.
     */
    private static final String START_AUTHOR_ELEMENT = "<author>";
    /**
     * End author element.
     */
    private static final String END_AUTHOR_ELEMENT = "</author>";
    /**
     * Start name element.
     */
    private static final String START_NAME_ELEMENT = "<name>";
    /**
     * End name element.
     */
    private static final String END_NAME_ELEMENT = "</name>";
    /**
     * Link element.
     */
    private static final String LINK_ELEMENT = "<link href=\"" + LINK_VARIABLE + "\" rel=\"self\" " + "type=\"application/atom+xml\" />";

    /**
     * Gets the id.
     * 
     * @return id
     */
    public String getId() {
        return id;
    }

    /**
     * Sets the id with the specified id.
     * 
     * @param id
     *            the specified id
     */
    public void setId(final String id) {
        this.id = id;
    }

    /**
     * Gets the link.
     * 
     * @return link
     */
    public String getLink() {
        return link;
    }

    /**
     * Sets the link with the specified link.
     * 
     * @param link
     *            the specified link
     */
    public void setLink(final String link) {
        this.link = link;
    }

    /**
     * Gets the title.
     * 
     * @return title
     */
    public String getTitle() {
        return title;
    }

    /**
     * Sets the title with the specified title.
     * 
     * @param title
     *            the specified title
     */
    public void setTitle(final String title) {
        this.title = title;
    }

    /**
     * Gets the subtitle.
     * 
     * @return subtitle
     */
    public String getSubtitle() {
        return subtitle;
    }

    /**
     * Sets the subtitle with the specified subtitle.
     * 
     * @param subtitle
     *            the specified subtitle
     */
    public void setSubtitle(final String subtitle) {
        this.subtitle = subtitle;
    }

    /**
     * Gets the author.
     * 
     * @return author
     */
    public String getAuthor() {
        return author;
    }

    /**
     * Sets the author with the specified author.
     * 
     * @param author
     *            the specified author
     */
    public void setAuthor(final String author) {
        this.author = author;
    }

    /**
     * Gets update date.
     * 
     * @return update date
     */
    public Date getUpdated() {
        return updated;
    }

    /**
     * Sets the update date with the specified update date.
     * 
     * @param updated
     *            the specified update date
     */
    public void setUpdated(final Date updated) {
        this.updated = updated;
    }

    /**
     * Adds the specified entry.
     * 
     * @param entry
     *            the specified entry
     */
    public void addEntry(final Entry entry) {
        entries.add(entry);
    }

    @Override
    public String toString() {
        final StringBuilder stringBuilder = new StringBuilder();
        stringBuilder.append(START_DOCUMENT);
        stringBuilder.append(START_FEED_ELEMENT);

        stringBuilder.append(START_ID_ELEMENT);
        stringBuilder.append(id);
        stringBuilder.append(END_ID_ELEMENT);

        stringBuilder.append(START_TITLE_ELEMENT);
        stringBuilder.append(title);
        stringBuilder.append(END_TITLE_ELEMENT);

        stringBuilder.append(START_SUBTITLE_ELEMENT);
        stringBuilder.append(subtitle);
        stringBuilder.append(END_SUBTITLE_ELEMENT);

        stringBuilder.append(START_UPDATED_ELEMENT);
        // using ISO-8601 instead of RFC-3339
        stringBuilder.append(DateFormatUtils.format(updated, DateFormatUtils.ISO_DATETIME_TIME_ZONE_FORMAT.getPattern(), TimeZone.getTimeZone(TIME_ZONE_ID)));
        stringBuilder.append(END_UPDATED_ELEMENT);

        stringBuilder.append(START_AUTHOR_ELEMENT);
        stringBuilder.append(START_NAME_ELEMENT);
        stringBuilder.append(author);
        stringBuilder.append(END_NAME_ELEMENT);
        stringBuilder.append(END_AUTHOR_ELEMENT);

        stringBuilder.append(LINK_ELEMENT.replace(LINK_VARIABLE, link));

        for (final Entry entry : entries) {
            stringBuilder.append(entry.toString());
        }

        stringBuilder.append(END_FEED_ELEMENT);

        return stringBuilder.toString();
    }
}
